Some industrial liquids require constant agitation for rheological or processing reasons. Typically, such fluids are dilatant or thixotropic in nature.
Additionally, slurries consisting of small solid particles suspended in a liquid medium typically require some level of agitation in order to keep the solids from settling. Often in industrial processes slurries are stored and mixed in tanks with a mechanical agitator such as a propeller. Circulation pumps then move the slurries from the tanks through distribution piping loops that deliver the slurries to points of use with unused slurry returning to the storage or day tanks.
This invention eliminates the need for mechanical agitators in tanks for many industrial processes. Eliminating the mechanical agitator reduces capital equipment, operation and maintenance costs and the potential for the mechanical agitator to fail and contaminate the fluid. In addition, some fluids are shear sensitive and can be damaged by mechanical agitation.
Rotating mechanical equipment (like mechanical agitators) tend to be rather “dirty” devices producing a continuous shower of wear by-products. This shower of particles poses a threat of contamination particularly in the pharmaceutical and semiconductor industries.
Others have utilized high purity gas bubbling through slurry tanks as a way to eliminate mechanical agitators. Gas bubble agitation has its drawbacks including the cost of a high purity gas, disposal of the spent gas, gas entrainment in the slurry, plugging of the gas spargers/septa, reduced energy efficiency and ineffectiveness at maintaining all but slow settling solids in suspension.
Thus, there still remains a need for a reliable, clean and relatively low shear means to mix industrial fluids in tanks.